TY - JOUR
T1 - In situ modification of polyisoprene by organo-nanoclay during emulsion polymerization for reinforcing natural rubber thin films
AU - Chouytan, Jadsadaporn
AU - Kalkornsurapranee, Ekwipoo
AU - Fellows, Christopher M.
AU - Kaewsakul, Wisut
N1 - Funding Information:
The authors would like to give special thanks to the researchers of Rubber Product Development Group, Faculty of Science, PSU, for their fruitful discussion and kind supports. This work was financially supported by the Natural Rubber Innovation Research Institute of PSU-Prince of Songkla University (Grant number: SCI581227S) as well as by the Graduate School of PSU under the scholarship "Thailand Education Hub for ASEAN Countries for PhD study (Grant number: TEH2557-001).".
Funding Information:
Funding: This work was financially supported by the Natural Rubber Innovation Research Institute of PSU—Prince of Songkla University (Grant number: SCI581227S) as well as by the Graduate School of PSU under the scholarship “Thailand Education Hub for ASEAN Countries for PhD study (Grant number: TEH2557-001).” Acknowledgments: The authors would like to give special thanks to the researchers of Rubber Product Development Group, Faculty of Science, PSU, for their fruitful discussion and kind supports.
Publisher Copyright:
© 2019 by the authors.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Nanoclay-modified polyisoprene latexes were prepared and then used as a reinforcing component in natural rubber (NR) thin films. Starve-fed emulsion (SFE) polymerization gives a higher conversion than the batch emulsion (BE), while the gel and coagulation contents from both systems are comparable. This is attributed to the SFE that provides a smaller average polymer particle size which in turn results in a greater polymerization locus, promoting the reaction rate. The addition of organo-nanoclay during synthesizing polyisoprene significantly lessens the polymerization efficiency because the nanoclay has a potential to suppress nucleation process of the reaction. It also intervenes the stabilizing efficiency of the surfactant-SDS or sodium dodecyl sulfate, giving enlarged average sizes of the polymer particles suspended in the latexes. TEM images show that nanoclay particles are attached on and/or inserted in the polymer particles. XRD and thermal (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) analyses were employed to assess the d-spacing of nanoclay structure in NR nanocomposite films, respectively. Based on the overall results, 5 wt% of nanoclay relative to the monomer content utilized to alter the polyisoprene during emulsion polymerization is an optimum amount since the silicate plates of nanoclay in the composite exhibit the largest d-spacing which maximizes the extent of immobilized polymer constituent, giving the highest mechanical properties to the films. The excessive amounts of nanoclay used, i.e., 7 and 10 wt% relative to the monomer content, reduce the reinforcing power because of the re-agglomeration effect.
AB - Nanoclay-modified polyisoprene latexes were prepared and then used as a reinforcing component in natural rubber (NR) thin films. Starve-fed emulsion (SFE) polymerization gives a higher conversion than the batch emulsion (BE), while the gel and coagulation contents from both systems are comparable. This is attributed to the SFE that provides a smaller average polymer particle size which in turn results in a greater polymerization locus, promoting the reaction rate. The addition of organo-nanoclay during synthesizing polyisoprene significantly lessens the polymerization efficiency because the nanoclay has a potential to suppress nucleation process of the reaction. It also intervenes the stabilizing efficiency of the surfactant-SDS or sodium dodecyl sulfate, giving enlarged average sizes of the polymer particles suspended in the latexes. TEM images show that nanoclay particles are attached on and/or inserted in the polymer particles. XRD and thermal (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) analyses were employed to assess the d-spacing of nanoclay structure in NR nanocomposite films, respectively. Based on the overall results, 5 wt% of nanoclay relative to the monomer content utilized to alter the polyisoprene during emulsion polymerization is an optimum amount since the silicate plates of nanoclay in the composite exhibit the largest d-spacing which maximizes the extent of immobilized polymer constituent, giving the highest mechanical properties to the films. The excessive amounts of nanoclay used, i.e., 7 and 10 wt% relative to the monomer content, reduce the reinforcing power because of the re-agglomeration effect.
KW - Elastomer
KW - Filler
KW - Latex
KW - Nanocomposite
KW - Reinforcement
KW - UT-Gold-D
UR - https://www.scopus.com/pages/publications/85071183491
U2 - 10.3390/polym11081338
DO - 10.3390/polym11081338
M3 - Article
AN - SCOPUS:85071183491
SN - 2073-4360
VL - 11
JO - Polymers
JF - Polymers
IS - 8
M1 - 1338
ER -